The Royal Free Hospital is one of only a few hospitals in the UK to offer a specialist metabolic kidney stone service.

Not all patients with kidney stones are suitable for this service, but if you are — after being referred by your urologist — we can:

  • advise on specific diets, or stop inappropriate diets and supplements
  • identify other health risks such as cardiovascular and bone disease
  • sometimes we can make a genetic diagnosis and give specific treatment for your stone disease

This is a separate service to the urology stone clinic — you will continue to be seen by your urologist regarding stone management/scanning as before.

We take national referrals for complex/specialist patients from urologists. Please email or write to:

Dr Shabbir Moochhala
Consultant Nephrologist 
Kidney and Urology Centre
Royal Free Hospital
Pond Street

If you are a new patient, you will be asked to undertake blood and 24-hour urine tests at least three weeks in advance of your first appointment. 

For some people, testing may not be necessary if you already have some results available.

For follow-up patients, most tests will be done after the clinic so we can discuss with you what tests are needed, and you can then book your blood tests online and/or collect urine collection bottles.

Urine samples can be dropped off in the renal blood testing area on third floor east of the Royal Free Hospital or at the laboratory (see details below).

Please email us any clinic letters or test results you have from other hospitals in advance of your appointment via the contact details on this page.

If you are collecting your 24-hour urine samples before you attend the Royal Free Hospital for an appointment or blood test, you could ask your local hospital to provide you with an empty 24-hour urine collection bottle. If you need to do this, please download and print this letter, which may help.

  1. Pick a time to start your 24-hour urine sample, for example when you wake up at 7am.
  2. At 6.59am empty your bladder into the toilet. This is last night’s urine, and we don’t want to collect it.
  3. From then on, every time you pass urine (even if it is at the same time as a bowel movement) you need to collect all the urine in the bottle you were given at the hospital.
  4. Keep doing this until 7am (ie 24 hours later) the following morning — you need to make yourself pass urine at exactly that time to complete the collection.
  5. Do not collect any more urine after this time. If you need to do a second collection, the next time you pass urine will be the first sample of your next 24-hour collection.
  6. If you make a mistake, discard all the urine and start again. There are no preservatives in the bottle so it is OK to do this.
  7. Try and return the completed collection to the Royal Free Hospital (occasionally we can arrange a courier if necessary) within 24-48 hours of completing the samples. Keep them in a cool place, but there is no need to keep them in the fridge. Return them to:

Biochemistry Specimen Reception 
First Floor East 
Royal Free Hospital 

The laboratory is open 24 hours a day. Just go to the 1st floor, go past the Lyndhurst Rooms and walk right to the end of the long corridor and you will find the hatch on the left. 

To reorder a prescription, please email with your hospital number and date of birth.

Our top tips for living with kidney stone disease are to:

  • always save any kidney stones that you pass
  • drink plenty of water throughout the day
  • eat a healthy and varied diet

There are also a number of leaflets from the The British Association of Urological Surgeons that you may find useful to read alongside any information the surgical team has already given you:

We are a research-active department, and we may invite you to take part in a number of research studies. 

For all of these, it is important to remember participation is completely optional, and your care will not be affected if you choose not to participate. 

If you would like more information on clinical research and trials, your clinician will be able to discuss this with you at your appointment.

Here is an overview of our current research studies:


RaDaR is the UK’s national registry for people who have rare kidney diseases. 

There are four conditions listed that are stone-forming. If you have one of these, we will ask if you would like to be registered with RaDaR. 

The advantage of being registered is that it allows us to contact you if new trials come up for patients with your condition, and we can also invite you to our popular patient information days. 

You can also communicate with us via Patients Know Best (formerly PatientView).

Genetics of kidney disease

There are ongoing research studies that enable us to collect samples (usually blood) for tests that you might need but are not available on the NHS. 

These are often research or genetic tests and if you would benefit from these, we will discuss them with you in advance. 

Primary hyperoxaluria

We are recruiting to interventional (drug) trials for some conditions such as primary hyperoxaluria. We are the only UK centre that has taken part in all trials for adult patients with this condition. 

If trials come up for other conditions, we will contact suitable patients.